They do the best they can, but there is only so much they can do unfortunately. All they can do is submit a copyright infringement notice to the website asking for it to be removed, most of these sites will comply, but it takes time to process. They aren’t able to take a website offline for without going to court, which would take even longer to get the content removed, but is not always an option due to international laws.
It’s like a game of Whack-A-Mole, you take out one and another pops up almost immediately.
Whenever you come across any pirated content, please send the link to **[EMAIL=“piracy@unrealengine.com”]piracy@unrealengine.com ** so that Epic is made aware of it. They do search as well but as mentioned there are so many of them it is hard to get them all.